…is the one at the winery Vistalba. It is located underground and has only three constructed walls. Entering the room, you get an unobstructed view of the top layers of soil typical of the region. On a side note, Vistalba is one of the few wineries in Argentina that produces Petit Verdot (of remarkable quality) as a stand-alone varietal. Plus, the steak offered in their on-site restaurant is one of the best I’ve had so far.